Sliding shaft power take off speed change

ABSTRACT

Apparatus is provided for the purpose of driving a power-takeoff shaft at one of two speeds the change of speed being effected by moving the shaft and its bearing housing longitudinally of the shaft so that a gear on the shaft meshes with one or other of two drive gears, the arrangement being that the housing is retained in one or other of the two positions by a spring urged ball locking device which can be easily unlocked to permit such movement.

United States Patent Thomas 1 51 July 11, 1972 SLIDING SHAFT POWER TAKEOFF R mm Cil SPEED CHANGE uNrrED sum-1s PATENTS m] as wmim m 1.1s1,0794/1916 Kelso ..74/391 x 8 2,474,789 6/1949 Perhacs 192/4119 [73]Assignee: Massey-Ferguson Services N.V., Curacao, 3,252,721 5/ I966Weasler 74/l l UX Nflhfllands Armlles 3.260.541 7/l966 Sadlfl et a]...74/1 1 x 122 FiiCdI Jan. 15. 1911 3.279.275 10/1966 Christie ..74/1s.4x

' I Appl' Primary Examiner-Leonard H. Gerin Attorney-Gerhardt. Greenlee& Farris 301 rot-61 11 Application mot-1w om Jan. 24, 1970 Great Britain..3.s57/70 [57] mm Apparatus is provided for the purpose of driving apower-take- 52 us. (:1 ..74/1s.4, 14/11, 192/489 speeds chug sPeed bangl92/67 R, 287/ I I9 R, 287/53 SS fected by moving the shaft and itsbearing housing longitu- 51 161. c1 ..Fl6h37/00,Fl6d 1 l/04,Fl6d 1/06dinally offlleshaflwflwtagear on the shah meshes with one [58] FieldolSearch ..74/l l, ISA, 15.6, [5.69, 356, Or other of two drive gears, thearrangement being that the 74/362, 363; 287/53 SS, H9 R; 192/701. 67 R.housing is retained in one or other of the two positions by a 1 48-91spring urged ball locking device which can be easily unlocked to permitsuch movement.

ilClalms,3Drawingflgures PNENTEDJIJLI 1 I972 SHEET 30F 3 Y \3 w/////////AAA@ W I vvy. mm fi M Q w w 3. w :1 I mm m R m s R Nq Q miwu [WWI/[KSLIDING SHAFT POWER TAKE OFF SPEED CHANGE This invention relates topower-talte-ofl shafis (hereinafter referred to as p.t.o. shafts) foragricultural and industrial tractors, and other vehicles.

it has heretofore been proposed to provide p.t.o. shafts which can bedriven at two different speeds to suit difl'erent implements orattachments, one speed being relatively low and of the order of 540 rpm.and the other speed being relatively high and of the order of l ,000rpm.

in one prior proposal, the p.t.o. shafi is axially shiftable between twopositions in one of which it engages exclusively with a gear driven atone speed, and in the other of which it engages exclusively with a geardriven at another speed. The shaft is journalled in the vehicle frame orbody and is resiliently biased in the rearward direction where it issplined in a sleeve to which can be fitted two different adapters whichdetermine the axial position of the shaft and hence the speed at whichit is to be driven. When it is desired to change from one p.t.o. shaftspeed to the other, it is necessary to remove one adapter and replace itby the other. This has meant, on the occasion of each change inadapters, the coupling or uncoupling of an adapter against the resilientbias of the shaft.

in another prior proposal, the p.t.o. shaft is splined in a drivingsleeve and can be reversed end-for-end in the sleeve to effect the speedchange. The shaft is longer at one end than at the other, with referenceto the spline location, and the longer end, when moved into thespeed-transmitting position, engages a clutch element disposed betweenthe sleeve and the driving gears to shift the clutch element out ofengagement with a gear rotatable at the relatively low speed and intoengagement with a gear rotatable at the relatively low speed and intoengagement with a gear rotatable at the relatively high speed, the shiftbeing against resilient means urging the clutch element to the lowerspeed position.

An object of the present invention is to provide a two-speed p.t.o.shaft mounting which obviates the need for p.t.o. shaft adapters orreversal of the p.t.o. shaft to effect the change of speed.

According to the present invention there is provided a twospeed p.t.o.shaft which is splined for driving engagement with either one of twodriven gears concentric with and spaced axially of the shaft, the lengthof the splining being such in relation to the axial spacing of saiddriven gears that the splines are out of engagement with both gears inan intermediate position when the shaft is moved axially from a positionwherein the splines engage either of the gears to a position wherein thesplines engage the other gear, and the shaft being locked in each ofsaid engaged positions against axial displacement relative to a fixedpart by an annular series of circumferentially Spaced balls between tworelatively axially moveable components one of which has alternativegrooves for the balls, the balls being held in engagement in eithergroove by a locking member which is resiliently loaded in the directionof ball captivation and is displaceable against the resilient loading torelease the balls and enable relative axial movement of the componentsto bring the other groove to the position in which it locates the balls.

Preferably, said two relatively axially moveable components are abearing housing concentric with and axially fast with the shaft, and atubular casing co-axial with and closely surrounding said bearinghousing, the latter mounting said annular series of circumferentiallyspaced balls and said tubular casing including in its inner peripheralsurface said alternative grooves for the balls.

Other objects and advantages of the invention will be readily apparentfrom the accompanying drawings and description and the essentialfeatures will be set forth in the appended claims. in the drawings:

FIG. 1 is a longitudinal sectional view of part of the drive of a p.t.o.shaft according to the present invention and showing the members in twodifferent positions on opposite sides of the axis of the p.t.o. shaft;

FlG.2isasimilarviewtothatofFlG. l andshowingthe construction at the rearend of the p.t.o. shaft, the members being in one of said two differentpositions; and

FIG. 3 is a view corresponding to FIG. 2 and showing the members in theother of said two different positions.

Referring firstly to FIG. 1, the p.t.o. shaft is denoted l and hasformed thereon an annular set of teeth or splines ll which can engagewith either one of two driven gears 12 and 13 concentric with the shaft.ln the upper part of FIG. 1 the set of teeth 11 is engaged with therelatively high-speed gear 12 and in the lower part of FIG. I is engagedwith the relatively lowspeed gear 13.

The gears 12 and 13 are part of a gear set within a housing 14 and usedfor transmitting drive between the prime mover (not shown) of thetractor and driving shafts such as the p.t.o. shaft 10. The latterextends into the housing, through the hub 15 ofgear 13, and into asocltet 16 in the rear end ofa shaft 17 extending in a forward directionwith reference to the tractor. The shaft 17 is in constant-driverelationship with the relatively high-speed gear 12 through a clutchmember 18 having a hub 19 on which the gear 12 is splined and locked andthrough which the p.t.o. shaft freely extends in its relatively lowspeedposition.

The hub is supported from the p.t.o. shaft 10 by means of rollerbearings 20 and 21 and has splines 22 adapted to be engaged by the setof teeth ii in the relatively low-speed position of the p.t.o. shaft,and the hub 19 has splines 23 adapted to be engaged by the set of teethii in the relatively highspeed position of the p.t.o. shaft. Rollerbearings 24 and 25 are provided in the socket 16 to receive the end ofthe p.t.o. shaft 10, the bearing 24 being operative at all times and thebearing 25 being operative only in the relatively high-speed position ofthe p.t.o. shaft.

Referring now to FIGS. 2 and 3 of the drawings, which show theconstruction at the outward or rear end of the p.t.o. shaft 10, abearing housing supporting the p.t.o. shaft i0 is axially fast with theshaft and can itself occupy two positions in a tubular casing 32, thesepositions being illustrated in FIGS. 2 and 3 and determining,respectively, the relatively low-speed and relatively high-speedpositions of the shaft. The bearing housing 30 includes in its externalperiphery a circumferential set of equally-spaced cages housing balls 33which are a rolling fit in the cages, and the tubular casing 32 includesin its inner periphery surface two longitudinally spaced annular grooves34 and 35 in each of which the balls 33 can be engaged to permitrotation of the shaft at the speed determined by whichever one of thegears l2 and 13 is engaged by the teeth or splines 11 of the shaft. Whenthe groove 35 is engaged by the balls 33, as in FIG. 2, the gear 12 isengaged by the teeth or splines 11, and when the groove 34 is engaged bythe balls 33, as in FIG. 3, the gear 13 is engaged by the teeth orsplines 11. The bearing housing 30 has annular recesses opening,respectively, in the forward and rearward directions and separated by aradial wall 36 which defines the bottom of each of the recesses and atwhose inner periphery is a ledge locating a C-section sealing ring 37bearing on the shaft 10. The forweirdly-opening recess accommodates anannular ball bearing 38 whose inner race 39 is locked on the shaft byabutment at one end of a shoulder on the shaft, and by a spring clip 40engaged on the shaft and abutting the other end of the inner race. Theouter race 41 of the bearing 38 is locked to the bearing housing 30 byabutment at one end against an annular shoulder at the angle between thepart 30 and the wall of the forwardly opening recess, and by a springclip 42 engaged in said wall. The annular ball bearing 38 thus preventsaxial movement of the bearing housing 30 relative to the shaft 3i.

An annular sleeve locking member 43 encircles the shaft and penetratesinto the rearwardly opening recess of the bearing housing, being urgedagainst the wall 36 by a spring 44 located about the member 43 in anannular ledge in the rear outer periphery of the member. The rear end ofthe spring 44 abuts a spring clip 45 bedded in the inner periphery ofthe wall of the rearwardly opening recess. The annular sleeve lockingmember 43 is located circumferentially by a series of involute splines55 formed on both the sleeve 43 and the housing 30. The bearing housing30 is held circumferentially fast with the tubular casing 32 by alocating pin 56 oo-operating with an axial groove cut in the outerperiphery of the housing 30. A disk 46 is apertured centrally to fitover the rearwardly protruding end of the member 43 and abuts the rearend of the bearing housing 30. The disk is located on the member 43 by aspring clip 47.

The locking member 43 is formed in its forward outer periphery with aperipheral groove 48 providing a land for the balls 33 to enable thelatter to be disengaged from the groove 34 or 35 when adjustment of thep.t.o. shaft is to be effected to change from engagement with one to theother of the gears 12 and 13. To enable such shaft adjustment, the disk46 is pulled to the rear and takes with it the annular sleeve member 43against the action of the spring 44. The balls 33 move into the groove48 when the member 43 has been shifted by the necessary amount. Thebearing block 30, and with it the shaft 10, then moves with the lockingmember 43 and disk 46 relative to the tubular casing 32 so that the ballcages can be aligned with the appropriate grooves 34 and 35 into whichthe balls are then forced by allowing the locking member 43 to be thrustby the spring 44 until the disk 46 again abuts the rear end of thebearing housing 30. On the latter movement of the member 43 the ballsare forced along the ramp face 49 of the groove 48 and into the groove34 or 35 aligned with the ball cages.

A bellows seal 50 bridged between the disk 46 and the casing 32, and anipple 51 enables lubrication of the ball cages and races. Differentshaft ends 52 and 53 are illustrated in FIGS. 2 and 3, respectively. butthey take no part in the shaft adjustment and form no part of theinvention.

[ claim:

I. A two-speed p.t.o. shaft which is splined for driving engagement witheither one of two driven gears concentric with and spaced axially of theshaft, the length of the splining being such in relation to the axialspacing of said driven gears that the splines are out of engagement withboth gears in an intermediate position when the shaft is moved axiallyfrom a position wherein the splines engage either of the gears to aposition wherein the splines engage the other gear, and the shaft beinglocked in each of said engaged positions against axial displacementrelative to a fixed part by an annular series of circumferentiallyspaced balls between two relatively axially moveable components one ofwhich has alternative grooves for the bells, the balls being held inengagement in either groove by a locking member which is resilientlyloaded in the direction of ball captivation and is displaceable againstthe resilient loading to release the balls and enable relative axialmovement of the components to bring the other groove to the position inwhich it locates the balls.

2. A p.t.o. shaft as claimed in claim 1, in which said two relativelyaxially moveable components are a bearing housing concentric with andaxially fast with the shah, and a tubular casing co-axial with andclosely surrounding said bearing housing, the latter mounting saidannular series of circumferentially spaced balls and said tubular casingincluding in its inner peripheral surface said alternative grooves forthe balls.

3. A p.t.o. shaft as claimed in claim 2, in which said balls are locatedin the bearing housing in a circumferential set of equally spaced cages.

4. A p.t.o. shaft as claimed in claim 3, in which the bearing housinghas an annular recess extending axial from each end thereof andseparated by a radial wall which defines the bottom of each recess, oneof said recesses accommodating an annular ball bearing which supportssaid shaft.

5. A p.t.o. shaft as claimed in claim 4, in which said locking member islocated in said other recess and is in the form of an annular sleeveencircling the shaft.

6. A p.t.o. shaft as claimed in claim 5, in which said locking member issprin biased towards said radial wall.

7. A p.t.o. sh as claimed in claim 6, in which said locking member islocated circumferentially by a series of splines formed on the lockingmember and co-operating with complementary splines in said other recessof the bearing housing.

8. A p.t.o. shaft as claimed in claim 7, is held circumferential fastwith the tubular casing by a locating pin cooperating with an axialgroove in the outer periphery of the bearing housing.

9. A p.t.o. shaft as claimed in claim 8, in which a disk is provided onthe locking member to facilitate manual displacement thereof againstsaid resilient loading.

10. A p.t.o. shaft as claimed in claim 9, in which the locking member isprovided with a peripheral groove which provides a land for the balls toenable the latter to be disengaged from said alternative grooves so asto allow adjustment of the shaft.

11. A p.t.o. shaft as claimed in claim 10, in which a ramp face isprovided on the peripheral groove on the locking member so as tofacilitate return of said balls into said alternative grooves afteradjustment of the shaft.

i i I i 1

1. A two-speed p.t.o. shaft which is splined for driving engagement witheither one of two driven gears concentric with and spaced axially of theshaft, the length of the splining being such in relation to the axialspacing of said driven gears that the splines are out of engagement withboth gears in an intermediate position when the shaft is moved axiallyfrom a position wherein the splines engage either of the gears to aposition wherein the splines engage the other gear, and the shaft beinglocked in each of said engaged positions against axial displacementrelative to a fixed part by an annular series of circumferentiallyspaced balls between two relatively axially moveable components one ofwhich has alternative grooves for the balls, the balls being held inengagement in either groove by a locking member which is resilientlyloaded in the direction of ball captivation and is displaceable againstthe resilient loading to release the balls and enable relative axialmovement of the components to bring the other groove to the position inwhich it locates the balls.
 2. A p.t.o. shaft as claimed in claim 1, inwhich said two relatively axially moveable components are a bearinghousing concentric with and axially fast with the shaft, and a tubularcasing co-axial with and closely surrounding said bearing housing, thelatter mounting said annular series of circumferentially spaced ballsand said tubular casing including in its inner peripheral surface saidalternative grooves for the balls.
 3. A p.t.o. shaft as claimed in claim2, in which said balls are located in the bearing housing in acircumferential set of equally spaced cages.
 4. A p.t.o. shaft asclaimed in claim 3, in which the bearing housing has an annular recessextending axial from each end thereof and separated by a radial wallwhich defines the bottom of each recess, one of said recessesaccommodating an annular ball bearing which supports said shaft.
 5. Ap.t.o. shaft as claimed in claim 4, in which said locking member islocated in said other recess and is in the form of an annular sleeveencircling the shaft.
 6. A p.t.o. shaft as claimed in claim 5, in whichsaid locking member is spring biased towards said radial wall.
 7. Ap.t.o. shaft as claimed in claim 6, in which said locking member islocated circumferentially by a series of splines formed on the lockingmember and co-operating with complementary splines in said other recessof the bearing housing.
 8. A p.t.o. shaft as claimed in claim 7, is heldcircumferential fast with the tubular casing by a locating pinco-operating with an axial groove in the outer periphery of the bearinghousing.
 9. A p.t.o. shaft as claimed in claim 8, in which a disk isprovided on the locking member to facilitate manual displacement thereofagainst said resilient loading.
 10. A p.t.o. shaft as claimed in claim9, in which the locking member is provided with a peripheral groovewhich provides a land for the balls to enable the latter to bedisengaged from said alternative grooves so as to allow adjustment ofthe shaft.
 11. A p.t.o. shaft as claimed in claim 10, in which a rampface is provided on the peripheral groove on the locking member so as tofacilitate return of said balls into said alternative grooves afteradjustment of the shaft.